U.S. patent number 8,939,654 [Application Number 14/024,272] was granted by the patent office on 2015-01-27 for ruggedized multi-fiber fiber optic connector with sealed dust cap.
This patent grant is currently assigned to ADC Telecommunications, Inc.. The grantee listed for this patent is ADC Telecommunications, Inc.. Invention is credited to Yu Lu, Gregory J. Schaible.
United States Patent |
8,939,654 |
Lu , et al. |
January 27, 2015 |
Ruggedized multi-fiber fiber optic connector with sealed dust
cap
Abstract
A fiber optic connector and fiber optic cable assembly is
disclosed. The assembly includes a fiber optic cable having a
plurality of optical fibers. The assembly also includes a connector
body, a multi-fiber ferrule and a protective housing. The fiber
optic cable is anchored to a proximal end of the connector body and
the multi-fiber ferrule is mounted at a distal end of the connector
body. The multi-fiber ferrule supports end portions of optical
fibers of the optical fiber cable. The protective housing mounts
over the connector body. A dimensionally recoverable sleeve
prevents contaminants from entering the protective housing through
a proximal end of the protective housing. A dust cap and sealing
member prevent contaminants from entering the protective housing
through a distal end of the protective housing.
Inventors: |
Lu; Yu (Eden Prairie, MN),
Schaible; Gregory J. (Lakeville, MN) |
Applicant: |
Name |
City |
State |
Country |
Type |
ADC Telecommunications, Inc. |
Berwyn |
PA |
US |
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Assignee: |
ADC Telecommunications, Inc.
(Berwyn, PA)
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Family
ID: |
50338928 |
Appl.
No.: |
14/024,272 |
Filed: |
September 11, 2013 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140086534 A1 |
Mar 27, 2014 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61706414 |
Sep 27, 2012 |
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Current U.S.
Class: |
385/60 |
Current CPC
Class: |
G02B
6/3849 (20130101); G02B 6/38 (20130101); G02B
6/4465 (20130101); G02B 6/3885 (20130101) |
Current International
Class: |
G02B
6/38 (20060101) |
Field of
Search: |
;385/60 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2 354 718 |
|
Mar 2002 |
|
CA |
|
195 17 750 |
|
Nov 1996 |
|
DE |
|
0 125 398 |
|
Nov 1984 |
|
EP |
|
1 122 564 |
|
Aug 2001 |
|
EP |
|
2 148 537 |
|
May 1985 |
|
GB |
|
61-9612 |
|
Jan 1986 |
|
JP |
|
7-234344 |
|
Sep 1995 |
|
JP |
|
8-234042 |
|
Sep 1996 |
|
JP |
|
8-262271 |
|
Oct 1996 |
|
JP |
|
2002-82257 |
|
Mar 2002 |
|
JP |
|
2008-116840 |
|
May 2008 |
|
JP |
|
2011-95410 |
|
May 2011 |
|
JP |
|
571134 |
|
Jan 2004 |
|
TW |
|
592934 |
|
Jun 2004 |
|
TW |
|
WO 01/27673 |
|
Apr 2001 |
|
WO |
|
WO 2004/028993 |
|
Apr 2004 |
|
WO |
|
WO 2009/011799 |
|
Jan 2009 |
|
WO |
|
WO 2010/090211 |
|
Aug 2010 |
|
WO |
|
WO 2011/087941 |
|
Jul 2011 |
|
WO |
|
WO 2011/087942 |
|
Jul 2011 |
|
WO |
|
WO 2011/087944 |
|
Jul 2011 |
|
WO |
|
WO 2012/005407 |
|
Jan 2012 |
|
WO |
|
Other References
International Search Report and Written Opinion for
PCT/US2013/061619 mailed Jan. 22, 2014. cited by applicant .
Abe, K. et al., "Modal interference in a short fiber section: fiber
length, splice loss, cutoff, and wavelength dependences," Optical
Fiber Communication Conference, p. 139, No. ThA3 (Feb. 1991). cited
by applicant .
De Jong, M., "Cleave and crimp fiber optic connector for field
installation," Optical Fiber Communication Conference, 1990
Technical Digest Series, vol. 1, Conference Edition, 3 pages (Jan.
1990). cited by applicant .
Duff, D.G. et al., "Measurements of modal noise in single-mode
lightwave systems," Conference on Optical Fiber Communication,
Paper No. TU01, 5 pages (Feb. 1985). cited by applicant .
FuseConnect.TM. ST Installation & Assembly Instructions, 14
pages (Mar. 2, 2011). cited by applicant .
Goodwin, J.C. et al., "Modal Noise in Short Fiber Sections,"
Journal of Lightwave Technology, vol. 9, No. 8, pp. 954-958 (Aug.
1991) Sep. 24, 1990. cited by applicant .
Harris, D. et al., "Azimuthal Dependence of Modal Interference in
Closely Spaced Single-Mode Fiber Joints," IEEE Photonics Technology
Letters, vol. 6, No. 10, pp. 1235-1237 (Oct. 1994). cited by
applicant .
Harris, D.O. et al., "Characterizing Modal Interference in Field
Installable Single-Mode Fiber Connectors Incorporating Short Fiber
Stubs," Technical Digest--Symposium on Optical Fiber Measurements,
NIST Special Publication 864, pp. 35-38 (Sep. 1994). cited by
applicant .
Heckmann, S., "Modal noise in single-mode fibres operated slightly
above cutoff," Electronics Letters, vol. 17, No. 14, pp. 499-500
(Jul. 1981). cited by applicant .
Li, M-J. et al., "Optical Fiber Design for Field Mountable
Connectors," Journal of Lightwave Technology, vol. 18, No. 3, pp.
314-319 (Mar. 2000). cited by applicant.
|
Primary Examiner: Le; Uyen Chau N
Assistant Examiner: Tran; Hoang
Attorney, Agent or Firm: Merchant & Gould P.C.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional
Patent Application Ser. No. 61/706,414, filed Sep. 27, 2012, which
application is hereby incorporated by reference in its entirety.
Claims
What is claimed is:
1. A fiber optic connector and fiber optic cable assembly
comprising: a fiber optic cable including a plurality of optical
fibers, at least one strength member for reinforcing the fiber
optic cable, and a cable jacket for containing the optical fibers
and the strength member; a connector body having a distal end and a
proximal end, the proximal end including an anchoring region for
anchoring the strength member of the fiber optic cable; a
multi-fiber ferrule mounted at the distal end of the connector
body, the multi-fiber ferrule supporting end portions of the
optical fibers; a protective housing mounted over the connector
body, the protective housing having a proximal end and a distal
end; a dimensionally recoverable sleeve positioned over the
proximal end of the protective housing and over the jacket of the
fiber optic cable to secure the jacket to the protective housing
and to prevent contaminants from entering the protective housing
through the proximal end of the protective housing; a dust cap that
mounts over the distal end of the protective housing; and a sealing
member that forms an environmental seal between the dust cap and
the protective housing for preventing contaminants from entering
the protective housing.
2. The fiber optic connector and fiber optic cable assembly of
claim 1, wherein the dust cap is secured to the distal end of the
protective housing by a threaded connection.
3. The fiber optic connector and fiber optic cable assembly of
claim 2, wherein the dust cap includes a proximal end and a distal
end, wherein the dust cap includes a main body that defines a
central dust cap axis that extends between the proximal and distal
ends of the dust cap, wherein the proximal end of the dust cap
receives the distal end of the protective housing, wherein the dust
cap includes a distal projection at the distal end of the dust cap,
wherein the distal projection projects distally outwardly from the
main body and is aligned along the central dust cap axis, and
wherein the distal projection has a plurality of wrench flats for
allowing a wrench to be used to tighten the threaded connection
between the dust cap and the distal end of the protective housing
by turning the dust cap relative to the protective housing about
the central dust cap axis.
4. The fiber optic connector and fiber optic cable assembly of
claim 3, wherein the distal projection defines an opening that
forms a pulling eye for allowing a pulling member to be connected
to the dust cap and used to pull the fiber optic connector and
cable assembly through a conduit.
5. The fiber optic connector and fiber optic cable assembly of
claim 4, wherein the opening extends through two of the flats of
the distal projection, and wherein the opening extends along an
opening axis that is perpendicular to the central dust cap
axis.
6. The fiber optic connector and fiber optic cable assembly of
claim 3, wherein the main body of the dust cap includes inner and
outer sleeves that extend around the central dust cap axis, wherein
an annular receptacle is defined between the inner and outer
sleeves, wherein the annular receptacle has an open end positioned
opposite from a closed end, wherein the open end faces in a
proximal direction, wherein the distal end of the protective
housing is received within the annular receptacle through the open
end of the annular receptacle, wherein the closed end of the
annular receptacle has a stepped configuration, wherein the stepped
configuration includes first and second radial steps separated by
an offset surface that extends distally from the first radial step
to the second radial step, wherein the first radial step extends
radially outwardly from the inner sleeve to the offset surface,
wherein the second radial step extends radially outwardly from the
offset surface to the outer sleeve, wherein the offset surface and
the second radial step form a deepest portion of the annular
receptacle, wherein the sealing member mounts over the inner sleeve
at a location adjacent to the first radial step, wherein the inner
sleeve includes first threads positioned within the annular
receptacle that face radially outwardly from the central dust plug
axis and that retain the sealing member on the inner sleeve,
wherein the outer sleeve includes second threads positioned within
the annular receptacle that face radially inwardly toward the
central dust plug axis, wherein the distal end of the protective
housing includes third threads that face radially outwardly from a
central housing axis of the protective housing, wherein the central
housing axis co-axially aligns with the central dust cap axis when
the dust cap is secured to the distal end of the protective
housing, and wherein the second and third threads mate to form the
threaded connection between the dust cap and the distal end of the
protective housing.
7. The fiber optic connector and fiber optic cable assembly of
claim 6, wherein the distal end of the protective housing defines
an interior bore including a main portion and a sealing portion,
wherein the sealing portion of the interior bore is distally and
radially offset from the main portion of the interior bore by a
ramp surface, wherein the sealing portion and the main portion of
the interior bore are cylindrical and the sealing portion has a
larger diameter than the main portion, wherein the sealing member
is axially compressed between the first radial step of the dust cap
and the ramp surface of the protective housing when the dust cap is
secured to the distal end of the protective housing, and wherein
the sealing member is radially compressed between the sealing
portion of the interior bore of the protective housing and a
cylindrical sealing surface of the inner sleeve of the dust cap
when the dust cap is secured to the distal end of the protective
housing.
8. The fiber optic connector and fiber optic cable assembly of
claim 7, wherein the interior bore of the protective housing
includes a chamfered portion that expands the interior bore as the
chamfered portion extends from the sealing portion of the interior
bore to a distal-most end of the protective housing.
9. The fiber optic connector and fiber optic cable assembly of
claim 8, wherein the distal-most portion of the protective housing
fits within the deepest portion of the annular receptacle when the
dust cap is secured to the protective housing.
Description
TECHNICAL FIELD
The present disclosure relates generally to optical fiber
communication systems. More particularly, the present disclosure
relates to fiber optic connectors used in optical fiber
communication systems.
BACKGROUND
Fiber optic communication systems are becoming prevalent in part
because service providers want to deliver high bandwidth
communication capabilities (e.g., data and voice) to customers.
Fiber optic communication systems employ a network of fiber optic
cables to transmit large volumes of data and voice signals over
relatively long distances. Optical fiber connectors are an
important part of most fiber optic communication systems. Fiber
optic connectors allow two optical fibers to be quickly optically
connected without requiring a splice. Fiber optic connectors can be
used to optically interconnect two lengths of optical fiber. Fiber
optic connectors can also be used to interconnect lengths of
optical fiber to passive and active equipment.
A typical fiber optic connector includes a ferrule assembly
supported at a distal end of a connector housing. A spring is used
to bias the ferrule assembly in a distal direction relative to the
connector housing. The ferrule functions to support an end portion
of at least one optical fiber (in the case of a multi-fiber
ferrule, the ends of multiple fibers are supported). The ferrule
has a distal end face at which a polished end of the optical fiber
is located. When two fiber optic connectors are interconnected, the
distal end faces of the ferrules abut one another and the ferrules
are forced proximally relative to their respective connector
housings against the bias of their respective springs. With the
fiber optic connectors connected, their respected optical fibers
are coaxially aligned such that the end faces of the optical fibers
directly oppose one another. In this way, an optical signal can be
transmitted from optical fiber to optical fiber through the aligned
end faces of the optical fibers. For many fiber optic connector
styles, alignment between two fiber optic connectors is provided
through the use of an intermediate fiber optic adapter.
A number of fiber optic connection systems have been developed for
use in outside environments. Such connection systems typically have
a ruggedized/hardened construction adapted for accommodating
substantial pull-out forces. Such connection systems are also
typically sealed to limit moisture intrusion. Example fiber optic
connection systems adapted for outside use are disclosed in U.S.
Pat. Nos. 6,648,520; 7,264,402; 7,572,065; 7,744,288; 7,762,726;
7,744,286; and 7,942,590.
SUMMARY
One aspect of the present disclosure relates to a fiber optic
connector and fiber optic cable assembly. The fiber optic connector
and fiber optic cable assembly includes a fiber optic cable
including a plurality of optical fibers, at least one strength
member for reinforcing the fiber optic cable, and a cable jacket
for containing the optical fibers and the strength member. The
fiber optic connector and fiber optic cable assembly also includes
a connector body having a distal end and a proximal end. The
proximal end of the connector body includes an anchoring region for
anchoring the strength member of the fiber optic cable. The fiber
optic connector and fiber optic cable assembly further includes a
multi-fiber ferrule and a protective housing. The multi-fiber
ferrule is mounted at the distal end of the connector body and
supports end portions of the optical fibers. The protective housing
is mounted over the connector body and includes a proximal end and
a distal end. The fiber optic connector and fiber optic cable
assembly further includes a dimensionally recoverable sleeve, a
dust cap and a sealing member. The dimensionally recoverable sleeve
is positioned over the proximal end of the protective housing and
over the jacket of the fiber optic cable to secure the jacket to
the protective housing and to prevent contaminants from entering
the protective housing through the proximal end of the protective
housing. The dust cap mounts over the distal end of the protective
housing. The sealing member forms an environmental seal between the
dust cap and the protective housing for preventing contaminants
from entering the protective housing through the distal end of the
protective housing.
A variety of additional inventive aspects will be set forth in the
description that follows. The inventive aspects can relate to
individual features and to combinations of features. It is to be
understood that both the foregoing general description and the
following detailed description are exemplary and explanatory only
and are not restrictive of the broad inventive concepts upon which
the embodiments disclosed herein are based.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a fiber optic connection system in
accordance with the principles of the present disclosure, the
system is shown in a non-connected state;
FIG. 2 is a perspective view showing the fiber optic connection
system of FIG. 1 in a connected state;
FIG. 3 is an exploded view of a first fiber optic connector and
cable assembly of the fiber optic connection system of FIG. 1;
FIG. 4 is an exploded view of a second fiber optic connector and
fiber optic cable assembly of the fiber optic connection system of
FIG. 1;
FIG. 5 is a cross-sectional view taken along section line 5-5 of
FIG. 1;
FIG. 6 is a cross-sectional view taken along section line 6-6 of
FIG. 1;
FIG. 7 is a cross-sectional view cut through a distal region of a
jack of the fiber optic connector and fiber optic cable assembly of
FIG. 4;
FIG. 8 is a cross-sectional view cut lengthwise through a connector
body of the jack of the fiber optic connector and fiber optic cable
assembly of FIG. 4;
FIG. 9 is a perspective view of a dust cap of the fiber optic
connector and fiber optic cable assembly of FIG. 4;
FIG. 10 is another perspective view of the dust cap of FIG. 9;
FIG. 11 is a distal end view of the dust cap of FIG. 9;
FIG. 12 is a proximal end view of the dust cap of FIG. 9;
FIG. 13 is a top view of the dust cap of FIG. 9;
FIG. 14 is a side view of the dust cap of FIG. 9; and
FIG. 15 is a cross-sectional view taken along section line 15-15 of
FIG. 14.
DETAILED DESCRIPTION
FIG. 1 illustrates a ruggedized (i.e., hardened) multi-fiber fiber
optic connection system 20 in accordance with the principles of the
present disclosure. The multi-fiber fiber optic connection system
20 includes a first fiber optic connector and fiber optic cable
assembly 22 and a second fiber optic connector and fiber optic
cable assembly 24 that are configured to interconnect to provide a
multi-fiber optical connection. The first fiber optic connector and
fiber optic cable assembly 22 includes a multi-fiber cable 26 and a
hardened connector in the form of a hardened plug 28. The hardened
plug 28 is mounted on the end of the multi-fiber cable 26. The
second fiber optic connector and fiber optic cable assembly 24
includes a multi-fiber cable 30 and a hardened connector in the
form of a hardened jack 32. The hardened jack 32 is mounted at the
end of the multi-fiber cable 30. As shown at FIG. 1, the hardened
plug 28 and the hardened jack 32 respectively include dust caps 34,
36. The dust cap 34 protects an interface end of the hardened plug
28 when the hardened plug 28 is not connected to the hardened jack
32. Similarly, dust cap 36 protects an interface end of the
hardened jack 32 when the hardened jack 32 is not connected to the
hardened plug 28. By removing the dust caps 34, 36 from the
hardened plug 28 and the hardened jack 32, the hardened plug 28 and
the hardened jack 32 can be coupled together as shown at FIG. 2.
When the hardened plug 28 and the hardened jack 32 are coupled
together, optical fibers corresponding to the multi-fiber cable 26
are optically coupled to optical fibers corresponding to the
multi-fiber cable 30.
Referring to FIG. 3, the hardened plug 28 of the first fiber optic
connector and fiber optic cable assembly 22 includes a connector
body 38 supporting a multi-fiber ferrule 40 at the interface end of
the hardened plug 28. An interface piece 42 mounts around the
multi-fiber ferrule 40 at a distal end of the connector body 38.
The multi-fiber ferrule 40 supports ends of a plurality of optical
fibers 44 (e.g., 12 optical fibers) corresponding to the
multi-fiber cable 26. Strength members (not shown) of the
multi-fiber cable 26 are secured to a proximal end of the connector
body 38. The hardened plug 28 also includes a protective housing 46
that mounts over the connector body 38. When assembled, the
interface piece 42 snaps within a proximal end of the protective
housing 46 such that the proximal end of the protective housing 46
and the interface piece 42 cooperate to define the interface end of
the hardened plug 28. It will be appreciated that end faces of the
optical fibers 44 secured within the multi-fiber ferrule 40 are
accessible from the interface end of the hardened plug 28. A
dimensionally recoverable sleeve 48 is secured over an outer jacket
of the multi-fiber cable 26 and also over a proximal end of the
protective housing 46. In this way, dimensionally recoverable
sleeve 48 provides a sealing function that prevents moisture of
contaminants from entering the interior of the protective housing
46 through the proximal end of the protective housing 46. A boot
300 mounts over the sleeve 48 and is retained on the proximal end
of the protective housing 46 by a press-fit or snap-fit connection.
The boot 300 is flexible and provides bend radius protection to the
cable 26.
Referring still to FIG. 3, the hardened plug 28 includes a sealing
member 50 (e.g., an o-ring seal) that is mounted on the protective
housing 46 and circumferentially surrounds a periphery of the
protective housing 46. The hardened plug 28 further includes a
retention nut 52 that mounts over the protective housing 46. The
retention nut 52 functions to retain the dust cap 34 over the
interface end of the hardened plug 28. For example, the retention
nut 52 includes internal threads 54 that mate with corresponding
external threads 56 of the dust cap 34 to secure the dust cap 34
over the interface end of the hardened plug 28. When the dust cap
34 is secured to the retention nut 52, a proximal end of the
retention nut 52 abuts against a shoulder 58 of the housing 46 to
stop distal movement of the retention nut 52 relative to the
protective housing 46. When the dust cap 34 is secured to the
protective housing 46 via the retention nut 52, the dust cap 34
engages the sealing member 50 to form a seal that prevents moisture
or other contaminants from entering the protective housing 46
through the distal end of the protective housing 46.
Referring to FIGS. 4, 6 and 7, the multi-fiber cable 30 of the
second fiber optic connector and fiber optic cable assembly 24
includes a plurality of optical fibers 62 (e.g., 12 optical
fibers). In FIG. 6, for clarity, only one of the fibers 62 is
shown. The multi-fiber cable 30 also includes at least one strength
member 64 for reinforcing the fiber optic cable 30. It will be
appreciated that the strength member 64 can be configured to
provide tensile and/or compressive reinforcement to the multi-fiber
cable 30. In certain embodiments, structures such as aramid yarn
and/or fiber reinforced epoxy rods can be used. In the depicted
embodiment, two strength members 64 are provided. The multi-fiber
cable 30 further includes a cable jacket 66 for containing the
optical fibers 62 and the strength members 64. As shown at FIG. 4,
the multi-fiber cable 30 is a flat drop-cable and the cable jacket
66 has an elongated profile when viewed in transverse cross
section.
Referring to FIG. 4, the hardened jack 32 of the second fiber optic
connector and the fiber optic cable assembly 24 includes a
connector body 70 having a distal end 72 and a proximal end 74. The
proximal end 74 includes an anchoring region 76 (see FIG. 6) for
anchoring the strength members 64 of the multi-fiber cable 30. As
depicted, the anchoring region 76 includes two parallel channels 78
in which the strength members 64 are received. The strength members
64 can be retained in the channels 78 by a material such as
adhesive (e.g., epoxy) and can also be mechanically gripped within
the channels 78. The channels 78 are best shown at FIG. 6.
Referring to FIG. 7, the hardened jack 32 includes a multi-fiber
ferrule 80 mounted at the distal end 72 of the connector body 70.
The multi-fiber ferrule 80 supports end portions of the optical
fibers 62 of the multi-fiber cable 30. Polished end faces of the
optical fibers 62 are positioned at a distal end of the multi-fiber
ferrule 80. The hardened jack 32 also includes an interface piece
82 that mounts around the multi-fiber ferrule 80. A spring 158 is
provided for biasing the multi-fiber ferrule 80 in a distal
direction relative to the connector body 70.
Referring to FIGS. 4 and 8, the hardened jack 32 includes a
protective housing 84 that mounts over the connector body 70. The
protective housing 84 has a distal end 86 and a proximal end 88.
The interface piece 82 fits within the distal end 86 of the
protective housing 84 and the multi-fiber ferrule 88 is positioned
within the interface piece 82. Thus, the interface piece 82, the
multi-fiber ferrule 80 and the distal end 86 of the protective
housing 84 cooperate to define the interface end of the hardened
jack 32. Referring to FIGS. 4 and 6, the hardened jack 32 further
includes a dimensionally recoverable sleeve 90 positioned over the
proximal end 88 of the protective housing 84 and over the jacket 66
of the multi-fiber cable 30 to secure the jacket 66 to the
protective housing 84 and to prevent moisture/contaminants from
entering the protective housing 84 through the proximal end 88 of
the protective housing 84. A boot 302 mounts over the sleeve 90 and
is retained on the proximal end of the housing 84 by a press-fit or
snap-fit connection. The boot 302 is flexible and provides bend
radius protection to the cable 30.
As shown at FIG. 4, the dust cap 36 is configured to mount over the
distal end 86 of the protective housing 84. A sealing member 92 is
used to form an environmental seal between the dust cap 36 and the
protective housing 84 for preventing moisture/contaminants from
entering the protective housing 84 through the distal end 86 of the
protective housing 84. The dust cap 36 is secured to the distal end
86 of the protective housing by a threaded connection. For example,
the dust cap 36 has internal threads 94 (see FIGS. 9 and 15) that
mate with external threads 96 at the distal end 86 of the proximal
housing 84 to secure the dust cap 36 on the protective housing
84.
Referring to FIGS. 9-15, the dust cap 36 corresponding to the
hardened jack 32 includes a distal end 100 and a proximal end 102.
The dust cap 36 also includes a main body 104 that defines a
central dust cap axis 106 (see FIG. 15) that extends between the
distal end proximal ends 100, 102 of the dust cap 36. The proximal
end 102 of the dust cap 36 is configured to receive the distal end
86 of the protective housing 84. The dust cap 36 includes a distal
projection 108 at the distal end 100 of the dust cap 36. The distal
projection 108 projects distally outwardly from the main body 104
and is aligned along the central dust cap axis 106. The distal
projection 108 has a plurality of wrench flats 110 for allowing a
wrench to be used to tighten the threaded connection between the
dust cap 36 and the distal end 86 of the protective housing 84 by
turning the dust cap 36 relative to the protective housing 84 about
the central dust cap axis 106. The distal projection 108 defines an
opening 112 that forms a pulling eye for allowing a pulling member
to be connected to the dust cap 36 and used to pull the fiber optic
connector and cable assembly 24 through a conduit (e.g., a conduit
in a building, an underground conduit, or other pipe or like
structure in which a fiber optic structure can be routed during
installation). The opening 112 extends through two of the wrench
flats 110 of the distal projection 108. The opening 112 extends
along an opening axis 114 that is perpendicular to the central dust
cap axis 106.
Referring to FIGS. 12 and 15, the main body 104 of the dust cap 36
includes inner and outer sleeves 116, 118 that extend around the
central dust cap axis 106. An annular receptacle 120 is defined
between the inner and outer sleeves 116, 118. The annular
receptacle 120 has an open end 122 opposite from a closed end 124.
The open end 122 of the annular receptacle 120 faces in a proximal
direction. The distal end 86 of the protective housing 84 of the
hardened jack 32 is received within the annular receptacle 120
through the open end 122 of the annular receptacle 120 (see FIG.
5). The closed end 124 of the annular receptacle 120 has a stepped
configuration. The stepped configuration includes first and second
radial steps 126, 128 separated by an offset surface 130. The
offset surface 130 extends distally from the first radial step 126
to the second radial step 128. The first radial step 126 extends
radially outwardly from the inner sleeve 116 to the offset surface
130. The second radial step 128 extends radially outwardly from the
offset surface 130 to the outer sleeve 118. The offset surface 130
and the second radial step 128 form a deepest portion 132 of the
annular receptacle 120. As best shown at FIG. 15, the sealing
member 92 (i.e., an annular sealing structure such as an o-ring)
mounts over the inner sleeve 116 at a location adjacent the first
radial step 126. The inner sleeve 116 includes inner-sleeve threads
134 positioned within the annular receptacle 120. The inner sleeve
threads 134 face radially outwardly from the central dust plug axis
106. The inner-sleeve threads 134 function to retain the sealing
member 92 within the annular receptacle 120 on the inner sleeve
116. The outer sleeve 118 defines the internal threads 94 of the
dust cap 36. The internal threads 94 are positioned within the
annular receptacle 120 and face radially inwardly from the outer
sleeve 118 toward the central dust plug axis 106.
As shown at FIG. 5, the protective housing 84 of the hardened jack
32 defines a central housing axis 136 that coaxially aligns with
the dust cap axis 106 when the dust cap 36 is secured to the distal
end 86 of the protective housing 84. The external threads 96 of the
hardened jack 32 are provided at the distal end 86 of the
protective housing 84 and are configured to face radially outwardly
from the central housing axis 136 of the protective housing 84. As
indicated above, the internal threads 94 provided on the outer
sleeve 118 of the dust cap 36 and the external threads 96 provided
at the distal end 86 of the protective housing 84 are configured to
mate and form a threaded connection between the dust cap 36 and the
protective housing 84.
As shown at FIGS. 7 and 8, the distal end 86 of the protective
housing 84 defines an interior bore 140 including a main portion
142 and a sealing portion 144. The sealing portion 144 of the
interior bore 140 is distally and radially offset from the main
portion 142 of the interior bore 140 by a ramp surface 146 (i.e.,
an incline surface). The sealing portion 144 and the main portion
142 of the interior bore 140 are cylindrical and the sealing
portion 144 has a larger diameter than the main portion 142. When
the dust cap 36 is secured to the distal end 86 of the protective
housing 84, the sealing member 92 is axially compressed between the
first radial step 126 of the dust cap 36 and the ramp surface 146
of the protective housing 84 (see FIG. 5). Additionally, still
referring to FIG. 5, the seal 92 is radially compressed between the
sealing portion 144 of the protective housing 84 and a cylindrical
sealing surface 148 of the inner sleeve 116 of the dust cap 36.
Referring again to FIGS. 5, 7 and 8, the interior bore 140 of the
protective housing 84 includes a chamfered portion 150 that expands
the diameter of the interior bore 140 of the chamfered portion 150
extends from the sealing portion 144 of the interior bore 140 to a
distal-most surface 152 of the protective housing 84. The chamfered
portion 150 is configured to facilitate inserting the distal end 86
of the protective housing 84 over the sealing member 92 within the
dust cap 36. When the dust cap 36 is fully installed on the
protective housing 84, the distal-most surface 152 of the
protective housing 84 fits within the deepest portion 132 of the
annular receptacle 120 of the dust cap 36 (see FIG. 5).
Referring to FIG. 5, the dust cap 36 includes a stop surface 154
defined by the outer sleeve 118 at a proximal-most extent of the
dust cap 36. In certain embodiments, stop surface 154 is oriented
in a plane, generally perpendicular to the dust cap axis 106. When
the dust cap 36 has been fully installed on the distal end 36 of
the protective housing 84, the stop surface 154 abuts against an
outer shoulder 156 of the protective housing 84 to provide a
positive stop. In certain embodiments, the outer shoulder 156 is
aligned along a plane that is perpendicular relative to the central
housing axis 136.
To interconnect the hardened plug 28 and the hardened jack 32, the
dust cap 34 is removed from the hardened plug 28 and the dust cap
36 is removed from the hardened jack 32. The hardened plug 28 and
the hardened jack 32 are then inserted axially together such that
the interface ends of the hardened plug 28 and the hardened jack 32
mate with one another. As the hardened plug 28 and the hardened
jack 32 are inserted together, the interface pieces 42, 82 mate
with one another to provide coarse alignment between the
multi-fiber ferrules 40, 80. As the hardened plug 28 and the
hardened jack 32 are continued to be axially inserted together,
ferrule pins 160 (see FIG. 3) of the multi-fiber ferrule 40 of the
hardened plug 28 are received within corresponding ferrule
alignment openings 162 (see FIGS. 4 and 7) defined by the
multi-fiber ferrule 80. The mating relationship between the
alignment pins 160 and the alignment openings 162 provide precise
alignment between the multi-fiber ferrules 40, 80 such that the
optical fibers 44 supported by the multi-fiber ferrule 40 coaxially
align with the corresponding optical fibers 62 supported by the
multi-fiber ferrule 80. In this way, the optical fibers 44, 62 of
the multi-fiber cables 26, 30 are optically connected together. The
hardened plug 28 and the hardened jack 32 are securely retained in
the fully inserted orientation by threading the retention nut 52 of
the first fiber optic connector and fiber optic cable assembly 22
onto the external threads 96 provided at the distal end 86 of the
protective housing 84 of the second fiber optic connector and fiber
optic cable assembly 24. During the insertion process between the
hardened plug 28 and the hardened jack 32, the distal end 86 of the
protective housing 84 slides over the sealing member 50 and the
sealing member 50 is compressed radially inwardly by the sealing
portion 144 of the interior bore and is compressed axially by the
ramp surface 146 of the interior bore 140. The distal-most surface
152 of the protective housing 84 can function as a stop surface
that is oriented and generally perpendicular relative to the
central housing axis 136 when the hardened plug 28 and the hardened
jack 32 are fully inserted together. The distal-most surface 152
can abut against a raised shoulder 165 provided on the exterior of
the protective housing 46 to provide a positive stop.
A dimensionally recoverable article is an article the dimensional
configuration of which may be made substantially to change when
subjected to treatment. Usually these articles recover towards an
original shape from which they have previously been deformed, but
the term "recoverable" as used herein, also includes an article
which adopts a new configuration even if it has not been previously
deformed.
A typical form of a dimensionally recoverable article is a heat
recoverable article, the dimensional configuration of which may be
changed by subjecting the article to heat treatment. In their most
common form, such articles comprise a heat-shrinkable sleeve made
from a polymeric material exhibiting the property of elastic or
plastic memory as described, for example, in U.S. Pat. No.
2,027,962 (Currie); U.S. Pat. No. 3,086,242 (Cook et al); and U.S.
Pat. No. 3,597,372 (Cook), the disclosures of which are
incorporated herein by reference. The polymeric material has been
cross-linked during the production process so as to enhance the
desired dimensional recovery. One method of producing a heat
recoverable article comprises shaping the polymeric material into
the desired heat-stable form, subsequently crosslinking the
polymeric material, heating the article to a temperature above the
crystalline melting point (or, for amorphous materials the
softening point of the polymer), deforming the article, and cooling
the article while in the deformed state so that the deformed state
of the article is retained. In use, because the deformed state of
the article is heat-unstable, application of heat will cause the
article to assume its original heat-stable shape.
In certain embodiments (e.g., in the depicted embodiments of the
present disclosure), the heat recoverable article is a sleeve or a
tube that can include a longitudinal seam or can be seamless. In
certain embodiments, the heat recoverable sleeve has a dual wall
construction including an outer, heat recoverable annular layer,
and an inner annular adhesive layer. In certain embodiments, the
inner annular adhesive layer includes a hot-melt adhesive layer.
Such adhesive layer can be used to bond the sleeve to components
such as a cable jacket or a portion of a connector. For example,
the dimensionally recoverable sleeve 90 can be adhesively bonded to
the cable jacket 66 and the proximal end 86 of the protective
housing 84. Similarly, sleeve 46 can be adhesively bonded to the
jacket of the cable 26 and to the protective housing 46.
In one embodiment, the heat recoverable sleeve is initially
expanded from a normal, dimensionally stable diameter to a
dimensionally heat unstable diameter that is larger than the normal
diameter. The heat recoverable sleeve is shape-set to the
dimensionally heat unstable diameter. This typically occurs in a
factory/manufacturing setting. The dimensionally heat unstable
diameter is sized to allow the heat recoverable sleeve to be
inserted over two components desired to be coupled together. After
insertion over the two components, the sleeve is heated thereby
causing the heat recoverable sleeve to shrink back toward the
normal diameter such that the sleeve radially compresses against
the two components to secure the two components together. The
adhesive layer is preferably heat activated during heating of the
sleeve.
From the foregoing detailed description, it will be evident that
modifications and variations can be made in the devices or methods
of the disclosure without departing from the spirit or scope of the
inventive aspects.
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